<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
    <p>row</p>
    <div class="row">
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
    </div>

    <p>column</p>
    <div class="column">
        <div class="item"></div>
        <div class="item"></div>
        <div class="item"></div>
    </div>
    <style>
        .row{
            display:flex;
            flex-direction: row;
        }
        .column{
            display:flex;
            flex-direction: column;
        }
        .item{
            background: red;
            height: 100px;
            width: 100px;
            border:1px solid #000;
        }
        </style>
</body>
</html>